JP2023118059A - Method for producing liquid crystal alignment film, light alignment agent, liquid crystal element, polymer and compound - Google Patents

Abstract

To provide a liquid crystal alignment agent that can give a liquid crystal alignment film having excellent liquid crystal alignment properties, touching durability and adhesion, and enables the production of a liquid crystal element with reduced bright dot defects.SOLUTION: A liquid crystal alignment film is produced by a method including the steps of: forming a coating layer with a liquid crystal alignment agent containing a polymer [A] having a moiety (a) represented by the formula (1); and irradiating the coating layer with light, to endow it with the ability to align liquid crystals. In the formula (1), A1 and A2 each represent a divalent aromatic ring group, where, A1 and/or A2 has a structure with a group represented by -OR1, -NR2R3 or -SR4 binding to an aromatic ring. B1 and B2 each represent a single bond, -O-, -S-, -NR5-, -CO-, *1-CO-O-, *1-O-CO-, *1-CS-O-, *1-O-CS-, *1-CO-NR6- or *1-NR6-CO-NR7-. X is a divalent hydrocarbon group.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a method for producing a liquid crystal alignment film, a photo-alignment agent, a liquid crystal element, a polymer and a compound.

Liquid crystal elements are used in a wide range of applications, from relatively large display devices such as liquid crystal televisions and information displays to small display devices such as smartphones. The performance of the liquid crystal element is determined by various characteristics such as the orientation of the liquid crystal, the magnitude of the pretilt angle, and the voltage holding ratio. In order to improve the performance of liquid crystal elements, conventionally, in addition to improving liquid crystal materials, improvements have been made to liquid crystal alignment films for aligning liquid crystals in a certain direction (see, for example, Patent Documents 1 and 2).

In Patent Document 1, in a liquid crystal aligning agent containing a polyamic acid that is a reaction product of a tetracarboxylic dianhydride and a diamine and a derivative thereof, di-tert-butyl {[adipoylbis(azanediyl)]bis( 5-amino-2,1-phenylene)}dicarbamate is disclosed to be incorporated into a liquid crystal aligning agent. Further, in Patent Document 2, polyimide obtained by using 4,4′-[ethane-1,2-diylbis(oxy)]bis(3-methylaniline) as a diamine can be contained in a liquid crystal aligning agent. disclosed.

WO2014/104015 WO2017/047596

A photo-alignment method is available as a method of forming a liquid crystal alignment film by imparting anisotropy to a film. In the photo-alignment method, a radiation-sensitive organic thin film formed on a substrate is irradiated with polarized or unpolarized radiation to impart anisotropy to the film, thereby controlling the orientation of liquid crystal molecules. . Compared to the conventional rubbing method, this method can suppress the generation of dust and static electricity in the process, so it is possible to suppress the occurrence of display defects and the decrease in yield due to dust and the like. is. There is also the advantage that the organic thin film formed on the substrate can be uniformly imparted with the ability to align the liquid crystal. On the other hand, when the photo-alignment method is applied, decomposition products such as polymers are likely to be generated by light irradiation, and display defects (bright spots) due to the decomposition products are likely to occur. In order to improve the quality of liquid crystal elements, it is required to suppress the generation of bright spots while improving liquid crystal orientation, which is one of the basic characteristics.

In mobile applications typified by smart phones, tablet PCs, and the like, attempts are being made to narrow the frame in order to achieve both a wider operating area of the touch panel and a smaller size of the display device. As one method for narrowing the frame, a method is known in which after forming a liquid crystal alignment film on the entire substrate surface, a sealing agent is applied onto the liquid crystal alignment film to bond the substrates together. On the other hand, when the sealing agent is arranged on the liquid crystal alignment film, force is likely to be applied to the alignment film portion where the sealing agent is arranged. Therefore, if the mechanical properties and adhesion of the liquid crystal alignment film are low, there is concern that the substrates are likely to separate from each other.

In recent years, most liquid crystal elements for smartphones and in-vehicle use are of the touch panel type, and are susceptible to external force from user's keystroke operations. From the viewpoint of improving the reliability of the liquid crystal element, the liquid crystal alignment film constituting the liquid crystal element is less susceptible to deterioration in display quality due to external force, and has good keying durability (also referred to as touch panel resistance). Something is also required.

The present invention has been made in view of the above-mentioned problems, and it is possible to obtain a liquid crystal alignment film excellent in liquid crystal alignment, keying durability, and adhesion, and to manufacture a liquid crystal element in which the occurrence of defective bright spots is suppressed. A main object of the present invention is to provide a liquid crystal aligning agent.

The present invention employs the following means to solve the above problems.

（式（１）中、Ａ^１及びＡ^２は、それぞれ独立して２価の芳香環基である。ただし、Ａ^１及びＡ^２の一方又は両方は、－ＯＲ^１、－ＮＲ^２Ｒ^３又は－ＳＲ^４で表される基が芳香環に結合した構造を有する。Ｒ^１、Ｒ^２及びＲ^４は、それぞれ独立して水素原子又は１価の有機基である。Ｒ^３は１価の有機基である。Ｂ^１及びＢ^２は、それぞれ独立して、単結合、－Ｏ－、－Ｓ－、－ＮＲ^５－、－ＣＯ－、＊^１－ＣＯ－Ｏ－、＊^１－Ｏ－ＣＯ－、＊^１－ＣＳ－Ｏ－、＊^１－Ｏ－ＣＳ－、＊^１－ＣＯ－ＮＲ^６－又は＊^１－ＮＲ^６－ＣＯ－ＮＲ^７－である。「＊^１」は、Ａ^１又はＡ^２との結合手を表す。Ｒ^５、Ｒ^６及びＲ^７は、それぞれ独立して水素原子又は１価の有機基である。Ｘは２価の炭化水素基である。「＊」は結合手を表す。） <1> A step of forming a coating film with a liquid crystal aligning agent containing a polymer [A] having a partial structure (a) represented by the following formula (1), and irradiating the coating film with light to align the liquid crystal A method for producing a liquid crystal alignment film, comprising a step of imparting an ability.

(In formula (1), A ¹ and A ² are each independently a divalent aromatic ring group, provided that one or both of A ¹ and A ² are —OR ¹ , —NR ² R ³ or It has a structure in which a group represented by —SR ⁴ is bonded to an aromatic ring, R ¹ , R ² and R ⁴ are each independently a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic B ¹ and B ² are each independently a single bond, —O—, —S—, —NR ⁵ —, —CO—, * ¹ —CO—O—, * ¹ —O—CO -, * ¹ -CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ⁶ -, or * ¹ -NR ⁶ -CO-NR ⁷ -, where “* ¹ ” represents A ¹ or represents a bond with A ^2. R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom or a monovalent organic group, X is a divalent hydrocarbon group, and "*" is a bond. represents a hand.)

（式（３）中、Ａ^３及びＡ^４は、それぞれ独立して２価の芳香環基である。ただし、Ａ^３及びＡ^４の一方又は両方は、－ＯＲ^１ａ又は－ＮＲ^２ａＲ^３ａで表される基が芳香環に結合した構造を有する。Ｒ^１ａ及びＲ^２ａは、それぞれ独立して１価の炭化水素基である。Ｒ^３ａは、水素原子又は１価の有機基である。Ｂ^３及びＢ^４は、それぞれ独立して、単結合、－Ｏ－、－Ｓ－、－ＮＲ^５ａ－、－ＣＯ－、＊^１－ＣＯ－Ｏ－、＊^１－Ｏ－ＣＯ－、＊^１－ＣＳ－Ｏ－、＊^１－Ｏ－ＣＳ－、＊^１－ＣＯ－ＮＲ^６ａ－又は＊^１－ＮＲ^６ａ－ＣＯ－ＮＲ^７ａ－である。Ｒ^５ａは１価の有機基である。Ｒ^６ａ及びＲ^７ａは、それぞれ独立して水素原子又は１価の有機基である。「＊^１」は、Ａ^３又はＡ^４との結合手を表す。Ｙは、Ｂ^３が－Ｏ－の場合に、炭素数１若しくは２のアルカンジイル基、２価の脂環式炭化水素基、又は２価の芳香族炭化水素基であり、Ｂ^３が＊^１－Ｏ－ＣＯ－の場合に、アルカンジイル基、炭素数４以上の脂肪族炭化水素環を有する２価の脂環式炭化水素基、又は２価の芳香族炭化水素基であり、Ｂ^３が－Ｏ－及び＊^１－Ｏ－ＣＯ－以外の場合に２価の炭化水素基である。）
＜５＞ 上記式（３）で表されるジアミン。 <2> A photo-alignment agent containing a polymer [A] having the partial structure (a) represented by the above formula (1).
<3> A liquid crystal device comprising a liquid crystal alignment film manufactured by the method of <1> above.
<4> A polymer containing a structural unit derived from a diamine represented by the following formula (3).

(In formula (3), A ³ and A ⁴ are each independently a divalent aromatic ring group, provided that one or both of A ³ and A ⁴ are —OR ^1a or —NR ^2a R ^3a ; The represented group has a structure bonded to an aromatic ring, R ^1a and R ^2a are each independently a monovalent hydrocarbon group, and R ^3a is a hydrogen atom or a monovalent organic group.B ³ and B ⁴ are each independently a single bond, -O-, -S-, -NR ^5a -, -CO-, * ¹ -CO-O-, * ¹ -O-CO-, * ¹ - CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ^6a - or * ¹ -NR ^6a -CO-NR ^7a -, R ^5a is a monovalent organic group, R ^6a and Each R ^7a is independently a hydrogen atom or a monovalent organic group, “* ¹ ” represents a bond with A ³ or A ⁴ , and Y is, when B ³ is —O—, an alkanediyl group having 1 or 2 carbon atoms, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, and when B ³ is * ¹ -O-CO-, an alkanediyl group, a divalent alicyclic hydrocarbon group having an aliphatic hydrocarbon ring with 4 or more carbon atoms, or a divalent aromatic hydrocarbon group, wherein B ³ is other than —O— and * ¹ —O—CO— In some cases, it is a divalent hydrocarbon group.)
<5> A diamine represented by the above formula (3).

ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal aligning film excellent in liquid-crystal aligning property, keying durability, and adhesiveness can be obtained, and the liquid crystal element by which generation|occurrence|production of the defect of a bright spot was suppressed can be obtained.

Below, the manufacturing method of the liquid crystal aligning agent of this indication, and a liquid crystal aligning film is demonstrated.

In addition, in this specification, a "hydrocarbon group" is a meaning including a chain|strand-shaped hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. A "chain hydrocarbon group" means a straight chain hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure in its main chain and is composed only of a chain structure. However, the chain hydrocarbon group may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, the alicyclic hydrocarbon group does not have to consist only of an alicyclic hydrocarbon structure, and may partially have a chain structure. An "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, the aromatic hydrocarbon group does not need to consist only of an aromatic ring structure, and may partially contain a chain structure or an alicyclic hydrocarbon structure. "Aromatic ring" is meant to include aromatic hydrocarbon rings and aromatic heterocycles. An "organic group" refers to an atomic group obtained by removing an arbitrary hydrogen atom from a compound containing carbon (ie, an organic compound).

（式（１）中、Ａ^１及びＡ^２は、それぞれ独立して２価の芳香環基である。ただし、Ａ^１及びＡ^２の一方又は両方は、－ＯＲ^１、－ＮＲ^２Ｒ^３又は－ＳＲ^４で表される基が芳香環に結合した構造を有する。Ｒ^１、Ｒ^２及びＲ^４は、それぞれ独立して水素原子又は１価の有機基である。Ｒ^３は１価の有機基である。Ｂ^１及びＢ^２は、それぞれ独立して、単結合、－Ｏ－、－Ｓ－、－ＮＲ^５－、－ＣＯ－、＊^１－ＣＯ－Ｏ－、＊^１－Ｏ－ＣＯ－、＊^１－ＣＳ－Ｏ－、＊^１－Ｏ－ＣＳ－、＊^１－ＣＯ－ＮＲ^６－又は＊^１－ＮＲ^６－ＣＯ－ＮＲ^７－である。「＊^１」は、Ａ^１又はＡ^２との結合手を表す。Ｒ^５、Ｒ^６及びＲ^７は、それぞれ独立して水素原子又は１価の有機基である。Ｘは２価の炭化水素基である。「＊」は結合手を表す。） 《Liquid crystal aligning agent》
The liquid crystal aligning agent of the present disclosure contains a polymer [A] having a partial structure (a) represented by formula (1) below.

(In formula (1), A ¹ and A ² are each independently a divalent aromatic ring group, provided that one or both of A ¹ and A ² are —OR ¹ , —NR ² R ³ or It has a structure in which a group represented by —SR ⁴ is bonded to an aromatic ring, R ¹ , R ² and R ⁴ are each independently a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic B ¹ and B ² are each independently a single bond, —O—, —S—, —NR ⁵ —, —CO—, * ¹ —CO—O—, * ¹ —O—CO -, * ¹ -CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ⁶ -, or * ¹ -NR ⁶ -CO-NR ⁷ -, where “* ¹ ” represents A ¹ or represents a bond with A ^2. R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom or a monovalent organic group, X is a divalent hydrocarbon group, and "*" is a bond. represents a hand.)

The liquid crystal aligning agent of the present disclosure is particularly suitable as a liquid crystal aligning agent (that is, photo-aligning agent) for forming a liquid crystal alignment film by photo-alignment treatment. Below, first, each component contained in the liquid crystal aligning agent of this indication, and the other component mix|blended arbitrarily as needed are demonstrated.

<Polymer [A]>
- About the partial structure (a) In the formula (1), the divalent aromatic ring group represented by A ¹ and A ² includes a divalent aromatic hydrocarbon group and a divalent aromatic heterocyclic group. be done. The divalent aromatic hydrocarbon group includes a group obtained by removing any hydrogen atom bonded to a carbon atom constituting a benzene ring, biphenyl ring, naphthalene ring or anthracene ring. The divalent nitrogen-containing aromatic heterocyclic group includes a group obtained by removing any hydrogen atom bonded to a carbon atom constituting a pyridine ring, pyrimidine ring, pyridazine ring or pyrazine ring. The divalent aromatic ring group represented by A ¹ and A ² is preferably a divalent aromatic hydrocarbon group among these, and any hydrogen bonded to a carbon atom constituting the ring of the benzene ring Groups with atoms removed are more preferred.

One or both of A ¹ and A ² has an electron-donating group represented by —OR ¹ , —NR ² R ³ or —SR ⁴ (hereinafter also referred to as “substituent F1”) bonded to the aromatic ring have a structure. By introducing a structure in which the substituent F1 is directly bonded to the aromatic ring into the polymer, the thermal rearrangement property is improved, and the liquid crystal orientation is improved. It is presumed that the strength was increased due to the structure that was easy to relax, and the keying durability was improved. In addition, by introducing the substituent F1, the solubility of the polymer can be enhanced, and the sensitivity of the polymer can be enhanced.

The monovalent organic group represented by R ¹ , R ² , R ³ or R ⁴ is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a thermally It is preferably a leaving group, more preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms or a thermally leaving group, and a monovalent hydrocarbon group having 1 to 5 carbon atoms or thermally leaving It is more preferable that it is a sexual group. The term "thermally releasable group" refers to a group that is desorbed by heat and replaced with a hydrogen atom. The thermally releasable group preferably has 15 or less carbon atoms, more preferably 10 or less carbon atoms, from the viewpoint of improving the resolvability by heat and reducing the amount of the desorbed portion remaining in the film. preferable.

Specific examples of monovalent hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, and aryl groups having 6 to 10 carbon atoms. . Among these, a monovalent hydrocarbon group having 1 to 6 carbon atoms is preferred, an alkyl group having 1 to 5 carbon atoms or a phenyl group is more preferred, and an alkyl group having 1 to 3 carbon atoms is even more preferred.

Specific examples when R ¹ is a thermally leaving group include an acetyl group, a benzoyl group, a benzyl group, a p-methoxyphenylbenzyl group, a methoxymethyl group, a tert-butoxycarbonyl group, a trimethylsilyl group, a triethylsilyl group, tert-butyldimethylsilyl group, trityl group and the like. Among these, the thermally leaving group represented by R ¹ is preferably an acetyl group, a methoxymethyl group or a tert-butoxycarbonyl group, more preferably an acetyl group or a tert-butoxycarbonyl group (Boc group).

Specific examples of R ² and R ³ being thermally eliminable groups include carbamate-based protecting groups, acyl-based protecting groups, amide-based protecting groups, imide-based protecting groups, and sulfonamide-based protecting groups. Among these, a carbamate-based protecting group is preferable because it is highly releasable by heat. Specific examples thereof include a tert-butoxycarbonyl group, a methoxycarbonyl group, a benzyloxycarbonyl group, a 1,1-dimethyl-2-haloethyloxycarbonyl group, an allyloxycarbonyl group, a 2-(trimethylsilyl)ethoxycarbonyl group, 9 -fluorenylmethyloxycarbonyl group, allyloxycarbonyl group and the like. Among these, the tert-butoxycarbonyl group (Boc group) is particularly preferable in that it is excellent in detachability by heat and can reduce the residual amount of the detached portion in the film.

Specific examples of R ⁴ being a thermally leaving group include a benzyloxymethyl group, p-methoxybenzyloxymethyl group, tert-butoxycarbonyl group, trimethylsilyl group and the like. Among these, a tert-butoxycarbonyl group (Boc group) is preferred.

Among the above, R ¹ , R ² and R ⁴ are preferably a hydrogen atom, a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a thermally eliminable group from the viewpoint of improving the liquid crystal orientation. , a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a phenyl group, or a thermally eliminable group. R ³ is preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms or a thermally leaving group, more preferably an alkyl group having 1 to 3 carbon atoms, a phenyl group or a thermally leaving group. preferable.

Specific examples of the substituent F1 include a hydroxy group, an alkoxy group having 1 to 5 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms (acetoxy group, propionyloxy group, etc.), a tert-butoxycarbonyloxy group, a carbon number 1-5 alkylamino group, dimethylamino group, diethylamino group, alkylamido group having 2-5 carbon atoms, N-(tert-butoxycarbonyl)amino group, N-(tert-butoxycarbonyl)-N-methylamino group , N-(tert-butoxycarbonyl)-N-ethylamino group, N,N-di(tert-butoxycarbonyl)amino group, thiol group, alkylthio group having 1 to 5 carbon atoms, and the like.

Among the above, the substituent F1 is preferably —OR ¹ or —NR ² R ³ , more preferably —OR ¹ , in that the effect of improving the liquid crystal orientation can be enhanced.

Both A ¹ and A ² have a substituent F1 bonded to an aromatic ring from the viewpoint of enhancing the effect of suppressing bright spots and improving the durability of keystrokes while obtaining good liquid crystal orientation and adhesion. preferably. The number of substituents F1 in A ¹ and the number of substituents F1 in A ² are each preferably 1 to 3, more preferably 1 or 2, and still more preferably 1.

The bonding position of the substituent F1 on the aromatic ring is not particularly limited. When the atom to which the substituent F1 is bonded and the atom to which B ¹ or B ² (X when B ¹ and B ² are single bonds) are adjacent to each other, the sensitivity to light can be increased, which is favorable This is preferable in that a liquid crystal element exhibiting good liquid crystal orientation can be obtained. In addition, it is preferable that A ¹ and A ² do not further have a substituent other than the substituent F1 on the ring portion of the aromatic ring.

R ^{5 , R 6 or R 7 contained in -NR 5 - , * 1 -CO-NR 6 -, * 1 -NR 6 -CO-NR 7 - for B 1 and B 2 is} a monovalent organic group; In some cases, the monovalent organic group is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms or a thermally releasable group. Specific and preferred examples of R ⁵ , R ⁶ or R ⁷ being a monovalent hydrocarbon group or thermally leaving group having 1 to 10 carbon atoms are described as specific and preferred examples of R ² and R ³ . groups. R ⁵ , R ⁶ and R ⁷ are preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a thermally leaving group, more preferably an alkyl group having 1 to 3 carbon atoms or a tert-butoxycarbonyl group.

From the viewpoint of obtaining a liquid crystal element exhibiting good liquid crystal orientation, B ¹ and B ² are, among others, -O-, -S-, -NR ⁵ -, -CO-, * ¹ -CO-O-, * ¹ -O-CO-, * ¹ -CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ⁶ - or * ¹ -NR ⁶ -CO-NR ⁷ -, and -O -, -S- or -NR ⁵ - is more preferred.

The divalent hydrocarbon group represented by X includes a chain hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms. groups. X is a chain hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or a carbon An aromatic hydrocarbon group having a number of 6 to 12 is preferable, and a straight-chain alkanediyl group having 1 to 5 carbon atoms in that the liquid crystal orientation can be made more excellent and the film density can be increased. is more preferred, and a methylene group or a 1,2-ethylene group is even more preferred.

（式（２）中、Ａ^１、Ａ^２、Ｂ^１、Ｂ^２及びＸは、上記式（１）と同義である。） The polymer [A] has the partial structure (a) in the main chain, that is, the partial structure (a) is the main part of the polymer [A], in that the effect of improving the liquid crystal orientation and the keystroke durability can be further enhanced. It preferably forms part of a chain. The main skeleton of polymer [A] is not particularly limited. It is easy to introduce the partial structure (a) into the main chain of the polymer, it is possible to form a liquid crystal alignment film having high affinity with liquid crystals and high mechanical strength, and there is a high degree of freedom in selecting monomers. , The polymer [A] preferably has a structural unit derived from a diamine having a partial structure (a) (hereinafter also referred to as a “specific diamine”), specifically represented by the following formula (2) It is preferable to have a structural unit derived from a compound having

(In formula (2), A ¹ , A ² , B ¹ , B ² and X have the same meanings as in formula (1) above.)

Here, the “main chain” refers to the “trunk” portion consisting of the longest chain of atoms in the polymer. In addition, it is permissible for this “trunk” portion to include a ring structure. That is, "having the partial structure (a) in the main chain" means that the partial structure (a) constitutes a part of the main chain. A "side chain" refers to a portion branched from the "trunk" of a polymer.

（式（２Ａ）中、Ｚ^１及びＺ^２は、それぞれ独立して、－ＯＲ^１、－ＮＲ^２Ｒ^３又は－ＳＲ^４で表される基である。ｋ１及びｋ２は、それぞれ独立して１又は２である。ｋ１が２の場合、複数のＺ^１は同一又は異なる。ｋ２が２の場合、複数のＺ^２は同一又は異なる。Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｂ^１、Ｂ^２及びＸは、上記式（１）と同義である。） The specific diamine is particularly preferably a compound represented by the following formula (2A).

(In formula (2A), Z ¹ and Z ² are each independently a group represented by —OR ¹ , —NR ² R ³ or —SR ⁴ ; k1 and k2 are each independently 1 or 2. When k1 is 2, multiple Z ¹ are the same or different, when k2 is 2, multiple Z ² are the same or different, ^{R 1} , R ² , R ³ , R ⁴ , B ¹ , B ² and X have the same meanings as in formula (1) above.)

In formula (2A), Z ¹ and Z ² are preferably groups represented by —OR ¹ or —NR ² R ³ .

When Z ¹ and Z ² are groups represented by —OR ¹ , R ¹ is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group or a thermally leaving group, and preferably has 1 to 5 carbon atoms. An alkyl group of 5 is more preferred, and an alkyl group of 1 to 3 carbon atoms is even more preferred. Further, B ¹ and B ² are -O-, -S-, -NR ⁵ -, -CO-, * ¹ -CO-O-, * ¹ -O-CO-, * ¹ -CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ⁶ - or * ¹ -NR ⁶ -CO-NR ⁷ -, preferably -O-, -S- or -NR ⁵ - more preferred. X is preferably an alkanediyl group having 1 or 2 carbon atoms, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, more preferably an alkanediyl group having 1 or 2 carbon atoms. .

When Z ¹ and Z ² are groups represented by —NR ² R ³ , R ² is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a phenyl group or a thermally leaving group, and R ³ is a carbon It is preferably an alkyl group, a phenyl group or a thermally eliminable group having numbers 1 to 3. B ¹ and B ² are preferably -O-, -S- or -NR ⁵ -, more preferably -O-. X is preferably an alkanediyl group having 1 to 5 carbon atoms, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, more preferably an alkanediyl group having 1 to 5 carbon atoms. , more preferably an alkanediyl group having 1 or 2 carbon atoms.

（式中、ｎは１～１８の整数である。） Specific examples of the specific diamine include compounds represented by the following formulas (4-1) to (4-24). In the formula, "Boc" represents a tert-butoxycarbonyl group (same below).

(Wherein, n is an integer from 1 to 18.)

In the compounds represented by the above formulas (4-1) to (4-24), the bonding position of the substituent F1 on the benzene ring is not particularly limited. The bonding position of the substituent F1 is relative to a group other than the primary amino group (that is, B ¹ or B ² in the above formula (1) (X when B ¹ and B ² are single bonds)) and preferably at the 2- or 3-position. In particular, when the bonding position of the substituent F1 is the 2-position with respect to a group other than the primary amino group, it is possible to increase the sensitivity and further improve the liquid crystal orientation, which is preferable.

In the polymer [A], the content ratio of the structural unit having the partial structure (a) (hereinafter also referred to as “structural unit (Ua)”) improves the liquid crystal orientation, adhesion and keystroke durability of the liquid crystal alignment film. From the viewpoint of sufficiently enhancing the effect and obtaining a liquid crystal device in which the generation of bright spots is sufficiently suppressed, it is 2 mol parts or more per 100 mol parts of the total amount of the monomer units of the polymer [A]. is preferred. The content of the structural unit (Ua) is more preferably 5 mol parts or more, still more preferably 10 mol parts or more, per 100 mol parts of the total amount of the monomer units of the polymer [A]. Further, the content ratio of the structural unit (Ua) can be appropriately set according to the main chain of the polymer [A]. It is less than the molar part. The number of structural units (Ua) possessed by the polymer [A] may be one, or two or more.

The specific diamine can be synthesized by appropriately combining standard methods of organic chemistry. One example is to synthesize a dinitro compound having a nitro group in place of the primary amino group of the diamine having the partial structure (a), and then convert the nitro group of the resulting dinitro compound to an amino group using an appropriate reducing system. method to convert

A method for synthesizing the dinitro compound can be appropriately selected according to the target compound. For example, a method of reacting a hydroxyl group-containing compound having an aromatic ring structure to which a substituent F1 is bonded and a halide having a group X preferably in an organic solvent in the presence of a base and, if necessary, a catalyst; A method of reacting a hydroxyl group-containing compound having an aromatic ring structure to which is bonded with a tosyl group-containing compound having a group X, preferably in an organic solvent in the presence of a base and, if necessary, a catalyst; A method in which an acid halide having an aromatic ring structure and an amino group-containing compound having a group X are condensed, preferably in an organic solvent, in the presence of a base and, if necessary, a catalyst; and an amino group-containing compound having a group X are preferably condensed in an organic solvent in the presence of a base and, if necessary, a catalyst.

The reduction reaction of the dinitro compound can be carried out preferably in an organic solvent using a catalyst such as palladium on carbon, platinum oxide, zinc, iron, tin, nickel and the like. Examples of organic solvents used here include ethyl acetate, toluene, tetrahydrofuran, and alcohols. However, the procedure for synthesizing the specific diamine is not limited to the above method.

（式（３）中、Ａ^３及びＡ^４は、それぞれ独立して２価の芳香環基である。ただし、Ａ^３及びＡ^４の一方又は両方は、－ＯＲ^１ａ又は－ＮＲ^２ａＲ^３ａで表される基が芳香環に結合した構造を有する。Ｒ^１ａ及びＲ^２ａは、それぞれ独立して１価の炭化水素基である。Ｒ^３ａは、水素原子又は１価の有機基である。Ｂ^３及びＢ^４は、それぞれ独立して、単結合、－Ｏ－、－Ｓ－、－ＮＲ^５ａ－、－ＣＯ－、＊^１－ＣＯ－Ｏ－、＊^１－Ｏ－ＣＯ－、＊^１－ＣＳ－Ｏ－、＊^１－Ｏ－ＣＳ－、＊^１－ＣＯ－ＮＲ^６ａ－又は＊^１－ＮＲ^６ａ－ＣＯ－ＮＲ^７ａ－である。Ｒ^５ａは１価の有機基である。Ｒ^６ａ及びＲ^７ａは、それぞれ独立して水素原子又は１価の有機基である。「＊^１」は、Ａ^３又はＡ^４との結合手を表す。Ｙは、Ｂ^３が－Ｏ－の場合に、炭素数１若しくは２のアルカンジイル基、２価の脂環式炭化水素基、又は２価の芳香族炭化水素基であり、Ｂ^３が＊^１－Ｏ－ＣＯ－の場合に、アルカンジイル基、炭素数４以上の脂肪族炭化水素環を有する２価の脂環式炭化水素基、又は２価の芳香族炭化水素基であり、Ｂ^３が－Ｏ－及び＊^１－Ｏ－ＣＯ－以外の場合に２価の炭化水素基である。） According to the present disclosure, a diamine represented by formula (3) below is provided.

(In formula (3), A ³ and A ⁴ are each independently a divalent aromatic ring group, provided that one or both of A ³ and A ⁴ are —OR ^1a or —NR ^2a R ^3a ; The represented group has a structure bonded to an aromatic ring, R ^1a and R ^2a are each independently a monovalent hydrocarbon group, and R ^3a is a hydrogen atom or a monovalent organic group.B ³ and B ⁴ are each independently a single bond, -O-, -S-, -NR ^5a -, -CO-, * ¹ -CO-O-, * ¹ -O-CO-, * ¹ - CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ^6a - or * ¹ -NR ^6a -CO-NR ^7a -, R ^5a is a monovalent organic group, R ^6a and Each R ^7a is independently a hydrogen atom or a monovalent organic group, “* ¹ ” represents a bond with A ³ or A ⁴ , and Y is, when B ³ is —O—, an alkanediyl group having 1 or 2 carbon atoms, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, and when B ³ is * ¹ -O-CO-, an alkanediyl group, a divalent alicyclic hydrocarbon group having an aliphatic hydrocarbon ring with 4 or more carbon atoms, or a divalent aromatic hydrocarbon group, wherein B ³ is other than —O— and * ¹ —O—CO— In some cases, it is a divalent hydrocarbon group.)

Specific and preferred examples of the monovalent hydrocarbon groups represented by R ^1a and R ^2a and the monovalent organic group represented by R ^3a in the above formula (3) are as follows: Specific examples and preferred examples of the monovalent hydrocarbon groups and monovalent organic groups exemplified for R ¹ , R ² and R ³ may be mentioned. R ^1a and R ^2a are preferably C 1-6 monovalent hydrocarbon groups, more preferably C 1-5 alkyl groups and phenyl groups, still more preferably C 1-3 is an alkyl group. R ^3a is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group or a thermally leaving group, more preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a tert-butoxycarbonyl group. be.

For specific examples and preferred examples of B ³ and B ⁴ , the explanations for B ¹ and B ² in formula (1) apply. Specific examples of the divalent hydrocarbon group represented by Y include the same groups as those exemplified as the group represented by X in formula (1).

When B ³ is —O—, Y is an alkanediyl group having 1 or 2 carbon atoms or a divalent aliphatic hydrocarbon ring having 4 or more carbon atoms from the viewpoint of enhancing the effect of improving liquid crystal orientation. A cyclic hydrocarbon group or a divalent aromatic hydrocarbon group is preferred. The divalent alicyclic hydrocarbon group having an aliphatic hydrocarbon ring having 4 or more carbon atoms preferably has a cyclohexane ring from the viewpoint of realizing good liquid crystal orientation and high film density. When ^B3 is -O-, Y is more preferably a methylene group or an ethylene group among these.

When B ³ is * ¹ -O-CO-, Y is preferably a linear alkanediyl group having 1 to 5 carbon atoms, more preferably a methylene group or an ethylene group. When B ³ is other than -O- and * ¹ -O-CO-, Y is a chain hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or 6 to An aromatic hydrocarbon group of 12 is preferable, and a linear alkanediyl group having 1 to 5 carbon atoms is more preferable in that the liquid crystal alignment can be made more excellent and the film density can be increased. A methylene group or an ethylene group is more preferred.

（式（３Ａ）中、Ｚ^３及びＺ^４は、それぞれ独立して、－ＯＲ^１ａ又は－ＮＲ^２ａＲ^３ａで表される基である。ｋ３及びｋ４は、それぞれ独立して１又は２である。ｋ３が２の場合、複数のＺ^３は同一又は異なる。ｋ４が２の場合、複数のＺ^４は同一又は異なる。Ｒ^１ａ、Ｒ^２ａ、Ｒ^３ａ、Ｂ^３、Ｂ^４及びＹは上記式（３）と同義である。） A compound represented by the following formula (3A) is particularly preferable as the diamine represented by the formula (3).

(In formula (3A), Z ³ and Z ⁴ are each independently a group represented by —OR ^1a or —NR ^2a R ^3a . k3 and k4 are each independently 1 or 2. When k3 is 2, multiple Z ³ are the same or different, when k4 is 2, multiple Z ⁴ are the same or different, and R ^1a , R ^2a , R ^3a , B ³ , B ⁴ and Y are Same as (3).)

Specific examples of the diamine represented by formula (3) include the above formulas (4-1) to (4-3), formula (4-6), formula (4-10) and formula (4-23). in which n is 1 or 2; and compounds represented by the above formulas (4-13), (4-18) and (4-22).

The polymer [A] is selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, among others, in that it has high affinity with liquid crystals, high mechanical strength, and can form a highly reliable liquid crystal alignment film. At least one is preferred.

· Polyamic acid When the polymer [A] is a polyamic acid, the polyamic acid (hereinafter also referred to as "polyamic acid [A]") reacts with a tetracarboxylic dianhydride and a diamine compound containing a specific diamine. can be obtained by

(tetracarboxylic dianhydride)
Examples of the tetracarboxylic dianhydrides used for synthesizing the polyamic acid [A] include aliphatic tetracarboxylic dianhydrides and aromatic tetracarboxylic dianhydrides. Examples of aliphatic tetracarboxylic dianhydrides include chain tetracarboxylic dianhydrides and alicyclic tetracarboxylic dianhydrides.

Specific examples of these include 1,2,3,4-butanetetracarboxylic dianhydride, ethylenediaminetetraacetic dianhydride and the like as chain tetracarboxylic dianhydride. The alicyclic tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, substituted cyclobutanetetracarboxylic dianhydride, and 2,3,5-tricarboxycyclopentylacetic dianhydride. , 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-di oxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3 .3.0]octane-2:4,6:8-dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, etc., 3,5,6-tricarboxy-2-carboxymethyl and norbornane-2:3,5:6-dianhydride.

Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, ethylene glycol bisanhydrotrimate, 4,4'-(hexafluoro isopropylidene)diphthalic anhydride, 4,4′-carbonyldiphthalic anhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride and the like. Further, as the tetracarboxylic dianhydride used for synthesizing the polyamic acid [A], the tetracarboxylic dianhydride described in JP-A-2010-97188 can be used. Tetracarboxylic dianhydrides can be used singly or in combination of two or more.

The tetracarboxylic dianhydride used in the synthesis of the polyamic acid [A] (and thus the polymer [A]) has high solubility, and can obtain a liquid crystal alignment film exhibiting good liquid crystal orientation and electrical properties. In terms of this, it preferably contains an aliphatic tetracarboxylic dianhydride, and more preferably contains an alicyclic tetracarboxylic dianhydride. The proportion of structural units derived from aliphatic tetracarboxylic dianhydride in polymer [A] is 20 mol% with respect to the total amount of structural units derived from tetracarboxylic dianhydride possessed by polymer [A]. It is preferably at least 40 mol %, more preferably at least 50 mol %.

（式（４）中、Ｒ^１１、Ｒ^１２、Ｒ^１３及びＲ^１４は、それぞれ独立して、水素原子又は置換基である。ただし、Ｒ^１１、Ｒ^１２、Ｒ^１３及びＲ^１４のうち１つ以上は置換基である。「＊」は結合手を表す。） Polymer [A] is derived from substituted cyclobutanetetracarboxylic dianhydride, among others, in that it is possible to reduce the occurrence of bright spots even after photo-alignment treatment by using it in combination with a specific diamine while making it a polymer with excellent photo-orientation. It is preferable to include a structural unit that Specifically, polymer [A] preferably contains a structural unit having a partial structure represented by the following formula (4).

(In Formula (4), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each independently a hydrogen atom or a substituent, provided that one of R ¹¹ , R ¹² , R ¹³ and R ¹⁴ The above are substituents."*" represents a bond.)

In formula (4), the substituent represented by R ¹¹ , R ¹² , R ¹³ and R ¹⁴ (that is, the substituent possessed by the substituted cyclobutanetetracarboxylic dianhydride) is an alkyl group having 1 to 6 carbon atoms , a halogenated alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogenated alkoxy group having 1 to 6 carbon atoms, a halogen atom, and the like. Among these, the substituents represented by R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are alkyl groups having 1 to 3 carbon atoms, halogenated alkyl groups having 1 to 3 carbon atoms, alkoxy groups having 1 to 3 carbon atoms, is preferably a group, a halogenated alkoxy group having 1 to 3 carbon atoms, or a halogen atom, more preferably an alkyl group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, or a fluorine atom; Methyl groups are particularly preferred.

Specific examples of the tetracarboxylic dianhydride having a partial structure represented by formula (4) include 1-methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl- 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3-trimethyl-1,2, 3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1-ethyl-1,2,3,4 -cyclobutanetetracarboxylic dianhydride, 1,3-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1-ethyl-3-methyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethoxy-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-diethoxy-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1 -trifluoromethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-di(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 3-di(trifluoromethoxy)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3-tri(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetra(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride and the like.

When the polymer [A] contains a structural unit derived from a substituted cyclotetracarboxylic dianhydride, the ratio of structural units derived from the substituted cyclotetracarboxylic dianhydride is the tetracarboxylic acid possessed by the polymer [A]. It is preferably 20 mol % or more, more preferably 40 mol % or more, and even more preferably 60 mol % or more, relative to the total amount of structural units derived from the dianhydride.

(Diamine compound)
The diamine compound used for synthesizing the polyamic acid [A] may be only the specific diamine. may be used. Other diamines include aliphatic diamines, aromatic diamines and diaminoorganosiloxanes. Aliphatic diamines include linear diamines and alicyclic diamines.

（式（Ｄ－１）中、Ｒ^２１及びＲ^２２は、それぞれ独立して、アルカンジイル基である。Ｒ^２３は、水素原子、炭素数１～３のアルキル基又は熱脱離性基である。ｎ１は１～３の整数である。ｎ１が２又は３の場合、複数のＲ^２２は互いに同一又は異なり、複数のＲ^２３は互いに同一又は異なる。）
で表される化合物等の主鎖型ジアミン；
ヘキサデカノキシ－２，４－ジアミノベンゼン、オクタデカノキシ－２，４－ジアミノベンゼン、オクタデカノキシ－２，５－ジアミノベンゼン、コレスタニルオキシ－３，５－ジアミノベンゼン、コレステリルオキシ－３，５－ジアミノベンゼン、コレスタニルオキシ－２，４－ジアミノベンゼン、コレステリルオキシ－２，４－ジアミノベンゼン、３，５－ジアミノ安息香酸コレスタニル、３，５－ジアミノ安息香酸コレステリル、３，５－ジアミノ安息香酸ラノスタニル、３，６－ビス（４－アミノベンゾイルオキシ）コレスタン、３，６－ビス（４－アミノフェノキシ）コレスタン、４－（４’－トリフルオロメトキシベンゾイロキシ）シクロヘキシル－３，５－ジアミノベンゾエート、１，１－ビス（４－（（アミノフェニル）メチル）フェニル）－４－ブチルシクロヘキサン、３，５－ジアミノ安息香酸＝５ξ－コレスタン－３－イル、下記式（Ｅ－１）

（式（Ｅ－１）中、Ｘ^I及びＸ^IIは、それぞれ独立して、単結合、－Ｏ－、＊－ＣＯＯ－又は＊－ＯＣＯ－（ただし、「＊」はジアミノフェニル基側との結合手を示す。）である。Ｒ^Ｉは、炭素数１～３のアルカンジイル基である。Ｒ^ＩＩは、単結合又は炭素数１～３のアルカンジイル基である。Ｒ^ＩＩＩは、炭素数１～２０のアルキル基、アルコキシ基、フルオロアルキル基、又はフルオロアルコキシ基である。ａは０又は１である。ｂは０～３の整数である。ｃは０～２の整数である。ｄは０又は１である。ただし、１≦ａ＋ｂ＋ｃ≦３である。）
で表される化合物等の側鎖型ジアミン等を、
ジアミノオルガノシロキサンとして、１，３－ビス（３－アミノプロピル）－テトラメチルジシロキサン等を、それぞれ挙げることができる。 Specific examples of other diamines include chain diamines such as metaxylylenediamine and hexamethylenediamine; and alicyclic diamines such as 1,4-diaminocyclohexane and 4,4′-methylenebis(cyclohexylamine). ; p-phenylenediamine, 1,4-diamino-2,5-dimethylbenzene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4-aminophenyl-4-aminobenzoate as aromatic diamines , 4,4′-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4 -aminophenoxy)propane, 1,6-bis(4-aminophenoxy)hexane, 6,6'-(pentamethylenedioxy)bis(3-aminopyridine), N,N'-di(5-amino-2 -pyridyl)-N,N'-di(tert-butoxycarbonyl)ethylenediamine, bis[2-(4-aminophenyl)ethyl]hexanedioic acid, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylamine, 4,4′-Diaminodiphenethylurea, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 1,4-bis(4 -aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-(phenylenediisopropylidene)bisaniline, 2, 6-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 3,6-diaminoacridine, diphenylamine structure-containing monomer, formula (D-1) below

(In formula (D-1), R ²¹ and R ²² are each independently an alkanediyl group. R ²³ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a thermally leaving group. n1 is an integer of 1 to 3. When n1 is 2 or 3, multiple R ²² are the same or different, and multiple R ²³ are the same or different.)
A main chain diamine such as a compound represented by;
Hexadecanoxy-2,4-diaminobenzene, Octadecanoxy-2,4-diaminobenzene, Octadecanoxy-2,5-diaminobenzene, Cholestanyloxy-3,5-diaminobenzene, Cholesteryloxy-3,5-diaminobenzene, Cholestanyl oxy-2,4-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholesteryl 3,5-diaminobenzoate, lanostanyl 3,5-diaminobenzoate, 3,6- Bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 3,5-diaminobenzoic acid = 5ξ-cholestan-3-yl, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, -O-, *-COO- or *-OCO- (wherein "*" is a diaminophenyl group side ), R ^I is an alkanediyl group having 1 to 3 carbon atoms, R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, and R ^III is an alkanediyl group having 1 to 3 carbon atoms. is an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group of 1 to 20. a is 0 or 1. b is an integer of 0 to 3. c is an integer of 0 to 2. d is 0 or 1. However, 1 ≤ a + b + c ≤ 3.)
A side chain type diamine such as a compound represented by
Examples of diaminoorganosiloxanes include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like.

Examples of the compound represented by the formula (D-1) include compounds represented by the following formulas (D-1-1) to (D-1-3). Examples of the compound represented by the formula (E-1) include compounds represented by the following formulas (E-1-1) to (E-1-4). Other diamines may be used singly or in combination of two or more.

In the polyamic acid [A], the ratio of structural units derived from a specific diamine sufficiently enhances the effect of improving the liquid crystal orientation of the liquid crystal alignment film, adhesion and keying durability, and sufficiently generates bright spots in the liquid crystal element. From the viewpoint of suppressing the is more preferable. As the specific diamine, one type may be used alone, or two or more types may be used in combination.

- Synthesis of polyamic acid Polyamic acid [A] can be obtained by reacting a tetracarboxylic dianhydride and a diamine compound together with a molecular weight modifier, if necessary. In the reaction for synthesizing polyamic acid [A], the ratio of the tetracarboxylic dianhydride and the diamine compound to be used is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.00 to 1 equivalent of the amino group of the diamine compound. A ratio of 2 to 2 equivalents is preferred. Examples of molecular weight modifiers include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. can be mentioned. The proportion of the molecular weight modifier used is preferably 20 parts by mass or less with respect to a total of 100 parts by mass of the tetracarboxylic dianhydride and the diamine compound used.

The synthesis reaction of polyamic acid [A] is preferably carried out in an organic solvent. At this time, the reaction temperature is preferably −20° C. to 150° C., and the reaction time is preferably 0.1 to 24 hours. Examples of organic solvents used in the reaction include aprotic polar solvents, phenolic solvents, alcoholic solvents, ketone solvents, ester solvents, ether solvents, halogenated hydrocarbons, and hydrocarbons. Specific examples thereof include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, Using one or more selected from the group consisting of xylenols and halogenated phenols as a reaction solvent, or using a mixture of one or more of these with other organic solvents (e.g. butyl cellosolve, diethylene glycol diethyl ether, etc.) is preferred. The amount of the organic solvent used is preferably such that the total amount of the tetracarboxylic dianhydride and the diamine is 0.1 to 50% by mass with respect to the total amount of the reaction solution.

By the above reaction, a polymer solution in which the polyamic acid [A] is dissolved is obtained. This polymer solution may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid [A] contained in the polymer solution.

- Polyamic acid ester When the polymer [A] is a polyamic acid ester, the polyamic acid ester (hereinafter also referred to as "polyamic acid ester [A]") is, for example, [I] esterified with polyamic acid [A] [II] A method of reacting a tetracarboxylic acid diester with a diamine compound containing a specific diamine, [III] A method of reacting a tetracarboxylic acid diester dihalide with a diamine compound containing a specific diamine , etc. Polyamic acid ester [A] may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. The reaction solution obtained by dissolving the polyamic acid ester [A] may be directly subjected to the preparation of the liquid crystal aligning agent, and the polyamic acid ester [A] contained in the reaction solution is isolated and then the liquid crystal aligning agent is prepared. may be served to

When the polyimide polymer [A] is a polyimide, the polyimide (hereinafter also referred to as "polyimide [A]") is imidized by dehydration ring closure of the polyamic acid [A] synthesized as described above, for example. can be obtained by The polyimide [A] may be a complete imidized product obtained by dehydrating and ring-closing all the amic acid structures that the precursor polyamic acid [A] had, and only a part of the amic acid structure is dehydrated and ring-closed. , a partially imidized product in which an amic acid structure and an imide ring structure coexist. The polyimide [A] preferably has an imidization rate of 20 to 99%, more preferably 30 to 90%. The imidization rate is expressed as a percentage of the ratio of the number of imide ring structures to the sum of the number of amic acid structures and the number of imide ring structures of polyimide. Here, part of the imide ring may be an isoimide ring.

Dehydration ring closure of polyamic acid [A] is preferably carried out by dissolving polyamic acid [A] in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution, and heating if necessary. In this method, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as a dehydrating agent. The dehydrating agent is preferably used in an amount of 0.01 to 20 mol per 1 mol of the amic acid structure of the polyamic acid [A]. Tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used as dehydration ring-closure catalysts. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol per 1 mol of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closure reaction include the organic solvents exemplified as those used in the synthesis of the polyamic acid [A]. The reaction temperature for the dehydration ring closure reaction is preferably 0 to 180°C. The reaction time is preferably 1.0 to 120 hours. In addition, the reaction solution containing polyimide [A] may be used for the preparation of the liquid crystal aligning agent as it is, or after isolating the polyimide [A], it may be used for the preparation of the liquid crystal aligning agent.

Polyimide [A] can be preferably used as the polymer [A] in that the mechanical strength of the liquid crystal alignment film can be increased. According to the studies of the present inventors, when the polyamic acid is imidized, the mechanical strength of the liquid crystal alignment film tends to decrease and the adhesion tends to decrease. On the other hand, polyimide is less soluble than polyamic acid, and there is a concern that it is likely to cause poor coatability and non-uniformity of the film. In this regard, since the polyimide [A] having the partial structure (a) exhibits good solubility, it is possible to form a liquid crystal alignment film with high mechanical strength while suppressing deterioration of coatability and deterioration of film uniformity. can.

The solution viscosity of the polymer [A] used for the preparation of the liquid crystal aligning agent preferably has a solution viscosity of 10 to 800 mPa s when the solution has a concentration of 10% by mass, and preferably 15 to 500 mPa s. It is more preferable to have a solution viscosity of The solution viscosity (mPa s) is E It is a value measured at 25°C using a type rotational viscometer.

The polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polymer [A] is preferably 1,000 to 500,000, more preferably 2,000 to 300, 000. In addition, the molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene equivalent number average molecular weight (Mn) measured by GPC is preferably 7 or less, more preferably 5 or less. In the preparation of the liquid crystal aligning agent, as the polymer [A], one type may be used alone, or two or more types may be used in combination.

<Other ingredients>
The liquid crystal aligning agent may contain a component different from the polymer [A] (hereinafter also referred to as "other components") in addition to the polymer [A], if necessary.

・Polymer [B]
The liquid crystal aligning agent of the present disclosure may further contain a polymer having no partial structure (a) (hereinafter also referred to as "polymer [B]") as a polymer component. The main skeleton of polymer [B] is not particularly limited. Other polymers include, for example, polyamic acids, polyamic acid esters, polyimides, polyorganosiloxanes, polyesters, polyenamines, polyureas, polyamides, polyamideimides, polybenzoxazole precursors, polybenzoxazoles, cellulose derivatives, polyacetals, (meth ) Acrylic polymers, styrene polymers, maleimide polymers, styrene-maleimide copolymers, and the like. From the viewpoint of obtaining a highly reliable liquid crystal device, the polymer [B] is a structural unit derived from a monomer having a polyamic acid, a polyamic acid ester, a polyimide, a polyorganosiloxane, and a polymerizable unsaturated carbon-carbon bond. At least one selected from the group consisting of polymers containing Polymers containing structural units derived from monomers having polymerizable unsaturated carbon-carbon bonds include (meth)acrylic polymers, styrene polymers, maleimide polymers, and styrene-maleimide copolymers. A coalescence etc. are mentioned.

When the polymer [B] is contained in the liquid crystal aligning agent, the content of the polymer [B] is preferably 1% by mass or more with respect to the total amount of the polymer [A] and the polymer [B]. 2% by mass or more is more preferable. Moreover, the content of the polymer [B] is preferably 95% by mass or less, more preferably 90% by mass or less, relative to the total amount of the polymer [A] and the polymer [B]. As the polymer [B], one type can be used alone or two or more types can be used in combination.

- Solvent The liquid crystal aligning agent of the present disclosure is prepared as a liquid composition in which the polymer [A] and optionally other components are preferably dispersed or dissolved in a suitable solvent.

An organic solvent is preferably used as the solvent. Specific examples include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, 1,3-dimethyl-2-imidazolidinone, phenol, γ- Butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol, 1-hexanol, 2-hexanol, propane-1,2- diol, 3-methoxy-1-butanol, ethylene glycol monomethyl ether, methyl lactate, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate, ethyl propionate, methyl methoxypropionate ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene Glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, Ethylene carbonate, propylene carbonate, propylene glycol monomethyl ether (PGME), diethylene glycol diethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol diacetate, cyclopentanone, cyclohexanone and the like can be mentioned. As the solvent, one type can be used alone or two or more types can be used in combination.

Other components contained in the liquid crystal aligning agent include, in addition to the above, for example, a cross-linking agent, an antioxidant, a metal chelate compound, a curing accelerator, a surfactant, a filler, a dispersant, a photosensitizer, and the like. mentioned. The mixing ratio of other components can be appropriately selected according to each compound within a range that does not impair the effects of the present disclosure.

The solid content concentration in the liquid crystal aligning agent (ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The solid content concentration of the liquid crystal aligning agent is preferably in the range of 1 to 10% by mass. A solid content concentration of 1% by mass or more is preferable in that a sufficient film thickness of the coating film can be ensured and a liquid crystal alignment film exhibiting better liquid crystal alignment can be obtained. On the other hand, when the solid content concentration is 10% by mass or less, the coating film can be made to have an appropriate thickness, a liquid crystal alignment film showing good liquid crystal alignment is easily obtained, and the viscosity of the liquid crystal alignment agent is moderate. There is a tendency that the coatability can be improved.

<<Liquid crystal alignment film and its manufacturing method>>
The liquid crystal alignment film of the present disclosure is manufactured using the liquid crystal alignment agent prepared as described above. The liquid crystal alignment film of the present disclosure includes a step of forming a coating film with a liquid crystal alignment agent containing the polymer [A] (coating film forming step), and a step of imparting liquid crystal alignment ability by irradiating the coating film with light. (Photo-alignment treatment step) and is preferably manufactured by a method including.

- Coating film formation process In the case of manufacture of a liquid crystal aligning film, first, a liquid crystal aligning agent is apply|coated on a board|substrate, Preferably a coating film is formed on a board|substrate by heating a coating surface. Examples of the substrate include glass such as float glass and soda glass; and transparent substrates made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin).

A method for applying the liquid crystal aligning agent to the substrate is not particularly limited. Application of the liquid crystal aligning agent to the substrate, for example, spin coating method, printing method (e.g., offset printing method, flexographic printing method, etc.), inkjet method, slit coating method, bar coater method, extrusion die method, direct gravure It can be carried out by a coater method, a chamber doctor coater method, an offset gravure coater method, an impregnation coater method, an MB coater method, or the like.

After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably carried out for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30-200° C., and the pre-baking time is preferably 0.25-10 minutes. Thereafter, the solvent is completely removed and, if necessary, a baking (post-baking) step is carried out for the purpose of thermal imidization of the amic acid structures present in the polymer. The baking temperature (post-baking temperature) at this time is preferably 80 to 280.degree. C., more preferably 80 to 250.degree. The post-bake time is preferably 5-200 minutes. The film thickness of the formed film is preferably 0.001 to 1 μm.

- Photo-alignment treatment step Subsequently, the coating film formed by the above-described steps is subjected to photo-alignment treatment in which light irradiation (radiation irradiation) is performed to impart liquid crystal alignment ability. A photo-alignment film is thus obtained. Light irradiation for photo-alignment is a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film after the pre-baking process and before the post-baking process, pre-baking process and post-baking process. It can be carried out by a method of irradiating the coating film while heating the coating film in either one or both.

As the radiation for irradiating the coating film, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used. Ultraviolet rays including light with a wavelength of 200 to 400 nm are preferred. When the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized or partially polarized, irradiation may be performed in a direction perpendicular to the substrate surface, obliquely, or a combination thereof. In the case of non-polarized radiation, the irradiation direction is oblique.

Examples of light sources to be used include low-pressure mercury lamps, high-pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, excimer lasers, and the like. The dose of radiation is preferably 200 to 30,000 J/m ² , more preferably 500 to 10,000 J/m ² . After light irradiation for imparting alignment ability, the substrate surface is treated with, for example, water, an organic solvent (eg, methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.), or a mixture thereof. A cleaning treatment or a substrate heating treatment may be performed.

≪Liquid crystal element≫
The liquid crystal element of the present disclosure includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The liquid crystal driving method in the liquid crystal element is not particularly limited. ) type, OCB (Optically Compensated Bend) type, and PSA (Polymer Sustained Alignment) type. The liquid crystal element can be produced, for example, by a method including the above-described coating film forming step and photo-alignment treatment step, and the following cell construction step.

The substrate used in the coating process depends on the desired mode of operation. For example, when manufacturing a TN-type, STN-type, or VA-type liquid crystal element, two substrates provided with patterned transparent conductive films are used. When manufacturing an IPS-type or FFS-type liquid crystal element, a substrate provided with electrodes patterned in a comb shape and a counter substrate provided with no electrode are used. As the transparent conductive film, a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), or the like can be used.

・Cell construction process In the cell construction process, two substrates on which liquid crystal alignment films are formed by the above-described photo-alignment treatment process are prepared, and a liquid crystal cell is manufactured by arranging the liquid crystal between the two substrates arranged opposite to each other. . In order to manufacture a liquid crystal cell, for example, two substrates are arranged facing each other with a gap therebetween so that the liquid crystal alignment films face each other, the peripheral portions of the two substrates are bonded together with a sealing agent, and the surfaces of the substrates and the sealing agent are bonded together. A method of injecting liquid crystal into a cell gap surrounded by and sealing the injection hole, a method of ODF method, and the like. As the sealant, for example, an epoxy resin or the like containing a curing agent and aluminum oxide spheres as spacers can be used.

As the liquid crystal, either positive type or negative type may be used. When negative liquid crystal is used in the IPS type and FFS type liquid crystal elements, transmission loss above the electrodes can be reduced and contrast can be improved, which is preferable. Further, in a photodegradable liquid crystal alignment film in which anisotropy is expressed by decomposing a polymer by light irradiation and thereby imparting liquid crystal alignment ability to the film, when a liquid crystal element is manufactured using a negative liquid crystal, radiation There is a tendency for the incidence of display defects (bright spots) due to decomposition products of polymers produced by irradiation to be high. In contrast, according to the liquid crystal aligning agent of the present disclosure, it is possible to obtain a high-quality liquid crystal element in which the generation of bright spots is suppressed. Liquid crystals include nematic liquid crystals and smectic liquid crystals, among which nematic liquid crystals are preferred.

When manufacturing a liquid crystal display device, subsequently, a polarizing plate is attached to the outer surface of the liquid crystal cell. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which iodine is absorbed while stretching orientation of polyvinyl alcohol is sandwiched between cellulose acetate protective films, or a polarizing plate composed of the H film itself.

The liquid crystal device of the present disclosure can be effectively applied to various uses. Specifically, for example, various display devices such as watches, portable game machines, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, information displays, etc. , a light control device, a retardation film, and the like.

According to the present disclosure described above, the following means are provided.

[Means 1] A step of forming a coating film from a liquid crystal aligning agent containing a polymer [A] having the partial structure (a) represented by the above formula (1), and irradiating the coating film with light to form a liquid crystal A method for producing a liquid crystal alignment film, comprising a step of imparting alignment ability.
[Means 2] The method for producing a liquid crystal alignment film according to [Means 1], wherein the polymer [A] has a structural unit derived from the compound represented by the formula (2).
[Means 3] The production of the liquid crystal alignment film according to [Means 1] or [Means 2], wherein the polymer [A] is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. Method.
[Means 4] The method for producing a liquid crystal alignment film according to any one of [Means 1] to [Means 3], wherein the polymer [A] has a structural unit derived from an aliphatic tetracarboxylic dianhydride.
[Means 5] The method for producing a liquid crystal alignment film according to [Means 4], wherein the aliphatic tetracarboxylic dianhydride has a partial structure represented by the above formula (4).
[Means 6] The method for producing a liquid crystal alignment film according to any one of [Means 1] to [Means 5], further comprising the polymer [B] not having the partial structure (a).
[Means 7] The method for producing a liquid crystal alignment film according to [Means 6], wherein the polymer [B] is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide.
[Means 8] A photo-alignment agent containing a polymer [A] having the partial structure (a) represented by the above formula (1).
[Means 9] A liquid crystal device comprising a liquid crystal alignment film produced by the method according to any one of [Means 1] to [Means 7].
[Means 10] A polymer containing a structural unit derived from the diamine represented by the above formula (3).
[Means 11] A diamine represented by the above formula (3).

Hereinafter, the embodiments will be described in more detail based on examples, but the present invention is not limitedly interpreted by the following examples.

In the following examples, the imidization rate of polyimide in the polymer solution was measured by the following method.
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting precipitate was thoroughly dried under reduced pressure at room temperature, dissolved in deuterated dimethylsulfoxide, and subjected to ¹ H-NMR measurement at room temperature using tetramethylsilane as a reference substance. . From the obtained ¹ H-NMR spectrum, the imidization rate [%] was determined by the following formula (I).
Imidation rate [%]=(1−(A ¹ /(A ² ×α)))×100 (I)
(In formula (I), A ¹ is the peak area derived from protons of the NH group appearing near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is the precursor of the polymer (polyamic acid ) is the number ratio of other protons to one proton of the NH group.)

The abbreviations of the compounds are as follows. In addition, below, the compound represented by Formula (X) (X is a symbol) may be simply referred to as "compound (X)".

(tetracarboxylic dianhydride)

(Diamine compound)

<Synthesis of Monomer>
[Synthesis Example 1A]
Compound (DA-1) was synthesized according to the following scheme.

4-Nitroguaiacol (23.72 g), 1,2-bis(tosyloxy)ethane (25.34 g), and potassium carbonate (23.63 g) are placed in a three-necked flask equipped with a reflux tube and a nitrogen inlet tube. Nitrogen was substituted. 130 mL of dimethylformamide was added thereto, the temperature was gradually raised to 80° C., and the mixture was stirred for 6 hours. After completion of the reaction, 650 mL of pure water was added to the reaction solution and stirred for 1 hour. The precipitated crystals were filtered under reduced pressure, and the crude product was washed with water and 2-propanol and dried under vacuum to obtain a powdery dinitro intermediate product (23.25 g, yield 93%).
Subsequently, a dinitro intermediate product (23.25 g) and 408 mg of palladium carbon were placed in a three-necked flask equipped with a reflux tube and a nitrogen inlet tube, and purged with nitrogen. 65 mL of tetrahydrofuran and 65 mL of ethanol degassed by nitrogen bubbling were added thereto, and the mixture was stirred while cooling to 5° C. to form a suspension solution. 18.5 mL of hydrazine monohydrate was slowly added dropwise to the suspension solution. After dropping, the temperature was gradually raised to 60° C. and stirred for 4 hours. The reaction solution was diluted with tetrahydrofuran, filtered through celite, and then concentrated to precipitate a product. The resulting precipitate was washed with THF, and the crystals were filtered under reduced pressure. The resulting crystals were washed with water and 2-propanol and dried in vacuo to obtain compound (DA-1) (16.04 g, yield 79%) as an ocher solid. The structure was confirmed by ¹ H-NMR spectrum, which is a nuclear magnetic resonance spectrum of intramolecular hydrogen atoms. The measured data are shown below.
¹ H-NMR (400 MHz, [D ₆ ]-DMSO) δ: 6.67 (dd, 2H), 6.26 (d, 2H), 6.04 (dd, 2H), 4.70 (s, 4H), 4.01 (s, 4H), 3.66 (s, 6H).

<Synthesis of polymer>
1. Synthesis of Polyamic Acid [Synthesis Example 1]
100 mol parts of the compound (TA-1) as a tetracarboxylic dianhydride, 40 mol parts of the compound (DA-1) as a diamine compound, 40 mol parts of the compound (DB-5) and 20 mol parts of the compound (DB-8). It was dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at room temperature for 6 hours to obtain a solution containing 15% by mass of polyamic acid (referred to as polymer (PA-1)).

[Synthesis Examples 2 to 9]
The same operation as in Synthesis Example 1 was performed except that the types and amounts of the tetracarboxylic dianhydride and diamine compound used were changed as shown in Tables 1 and 2, and polyamic acid (polymer (PA-2) to A solution containing 15% by mass of (PA-9)) was obtained.

2. Synthesis of Polyimide [Synthesis Example 10]
90 mol parts of compound (TA-1) and 10 mol parts of compound (TA-2) as tetracarboxylic dianhydrides, and 100 mol parts of compound (DA-1) as diamine compounds in N-methyl-2-pyrrolidone (NMP) and reacted at room temperature for 6 hours to obtain a solution containing 15% by mass of polyamic acid. Next, NMP was added to the obtained polyamic acid solution to make a solution having a polyamic acid concentration of 10% by mass, pyridine and acetic anhydride were added, and a dehydration ring-closing reaction was carried out at 60° C. for 4 hours. After the dehydration ring-closure reaction, the solvent in the system is replaced with new NMP to obtain a solution containing 15% by mass of a polyimide having an imidization rate of about 90% (this is referred to as a polymer (PI-1)). Ta.

[Synthesis Examples 11 to 20]
The type and amount of the tetracarboxylic dianhydride and diamine compound used are changed as shown in Table 3, and the amounts of pyridine and acetic anhydride are adjusted to synthesize the imidization rate as shown in Table 3. to obtain a solution containing 15% by mass of polyimide (polymers (PI-2) to (PI-11)).

<Preparation and Evaluation of Liquid Crystal Aligning Agent>
[Example 1]
1. Preparation of liquid crystal aligning agent A solution of the polymer (PA-1) obtained in Synthesis Example 1 and a solution of the polymer (PA-3) obtained in Synthesis Example 3 were mixed with the polymer (PA-1) and the polymer (PA-3) is mixed so that (PA-1) / (PA-3) = 30/70 (mass ratio) as a solid content, diluted with NMP and butyl cellosolve (BC), and the solvent composition is A solution having NMP/BC=80/20 (mass ratio) and a solid content concentration of 3.5% by mass was prepared. A liquid crystal aligning agent (AL-1) was prepared by filtering this solution through a filter having a pore size of 0.2 μm.

2. Manufacture of FFS type liquid crystal display element using photo-alignment method A glass substrate (referred to as a first substrate) having a flat plate electrode (bottom electrode), an insulating layer and a comb-shaped electrode (top electrode) laminated in this order on one side, In addition, a glass substrate (referred to as a second substrate) having no electrodes was prepared. Next, the liquid crystal aligning agent (AL-1) was applied to each of the electrode formation surface of the first substrate and one surface of the second substrate using a spinner, and heated (pre-baked) on a hot plate at 80° C. for 1 minute. Thereafter, drying (post-baking) was performed for 30 minutes in an oven at 150° C. in which the inside of the chamber was replaced with nitrogen to form a coating film having an average film thickness of 0.1 μm. The resulting coating film was subjected to photo-alignment treatment by irradiating 1,000 J/m ² of linearly polarized ultraviolet light containing a 254 nm emission line from the normal direction of the substrate using a Hg-Xe lamp. Note that this irradiation dose is a value measured using a photometer that measures at a wavelength of 254 nm. Subsequently, the coating film to which the optical alignment treatment was applied was heated in a clean oven at 150° C. for 30 minutes for heat treatment, thereby forming a liquid crystal alignment film.
Next, on one of the pair of substrates on which the liquid crystal alignment film was formed, an epoxy resin adhesive containing aluminum oxide spheres with a diameter of 3.5 μm was applied to the outer edge of the surface having the liquid crystal alignment film by screen printing. After that, the substrates were superimposed and pressure-bonded so that the projection direction of the polarization axis onto the substrate surface during light irradiation was antiparallel, and the adhesive was thermally cured at 150° C. for 1 hour. Next, a negative type liquid crystal (MLC-6608, manufactured by Merck Co.) was filled between the pair of substrates through the liquid crystal inlet, and the liquid crystal inlet was sealed with an epoxy adhesive to obtain a liquid crystal cell. Furthermore, in order to eliminate the flow alignment during liquid crystal injection, this was heated at 120° C. and then gradually cooled to room temperature. After that, polarizing plates were bonded to both outer sides of the substrates in the liquid crystal cell to obtain a liquid crystal display element. In addition, three or more liquid crystal display elements having different ultraviolet irradiation amounts can be produced by performing the above series of operations while changing the ultraviolet irradiation amount after post-baking in the range of 100 to 10,000 J/m ^{2 .} The manufactured liquid crystal display device with the exposure amount (optimal exposure amount) that showed the best alignment characteristics was used for the following evaluations.

3. Evaluation of liquid crystal orientation 2. The liquid crystal display element manufactured in 1. was left for 500 hours on a high-brightness backlight of 27,000 cd/m ² , and the liquid crystal orientation was evaluated by the rate of change α in retardation before and after irradiation with the backlight. Retardation was measured by Axoscan manufactured by Optoscience, and the rate of change α in retardation before and after backlight irradiation was calculated by the following formula (II). It can be said that the smaller the rate of change α, the better the liquid crystal orientation. "Excellent (◎)" when the rate of change α is 0.5% or less, "Good (○)" when it is greater than 0.5% and 1% or less, 2% greater than 1% A case of less than or equal to 2% was evaluated as "acceptable (Δ)", and a case of greater than 2% was evaluated as "bad (x)".
α=Δθ/θ1 (II)
(In formula (II), Δθ represents the retardation difference before and after irradiation, and θ1 represents the retardation value before irradiation.)
As a result, the liquid crystal orientation of this example was evaluated as "good (○)".

4. Evaluation of Bright Spots (Bright Spot Suppression Property) of Liquid Crystal Cell 2 above. The liquid crystal cell produced in 1. was observed with a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation) to evaluate the bright spot suppressing property. Specifically, the liquid crystal cell was placed between two polarizing plates arranged so that their polarization axes were orthogonal to each other, and the liquid crystal cell was observed with a polarizing microscope at a magnification of 5 (observation area: about 2500 μm×2500 μm). . It can be said that the smaller the number of bright spots, the smaller the decomposition products due to the photo-alignment treatment and the better. When the number of bright spots was 100 or more, it was rated as "bad (x)"; As a result, it was "good (○)" in this example.

5. Evaluation of keying durability by keying test 2 above. For the liquid crystal display element manufactured in 1., the liquid crystal orientation was evaluated after the keying test was performed. Evaluation was performed as follows. A silicone rubber pen 3R (manufactured by Touch Panel Laboratory Co., Ltd.) having a pen tip with a radius of 3 mm is set in the keying part (solenoid type) of a keying tester (manufactured by Touch Panel Laboratory Co., Ltd.). It was installed so that the tip was at the center position of the liquid crystal display element. After keying 10,000 times at 10 Hz with a load of 500 g using a silicone rubber pen, the liquid crystal display element was observed under a microscope (100 magnification), and the number of bright spots was counted. It can be said that the smaller the number of luminescent spots, the more excellent the durability against keying of the liquid crystal display element. "Excellent (◎)" when the number of bright spots is less than 30; "Good (○)" when the number is 30 or more and less than 50; (triangle|delta))", and the case where it was 100 or more was judged to be "defective (x)". As a result, this example was evaluated as "good (○)".

5. Evaluation of Adhesion 1 above. The liquid crystal aligning agent (AL-1) prepared in was applied to a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 2 minutes, and then in an oven at 230 ° C. in which the interior was replaced with nitrogen. A coating film having an average film thickness of 0.10 μm was formed by heating (post-baking) for 10 minutes. By repeating the same operation, two glass substrates each having a coating film formed thereon were produced. An ODF sealant (manufactured by Sekisui Chemical Co., Ltd., S-WB42) is applied to the coating film of one glass substrate on which the coating film is formed so that the width is 1 mm, and the coating film of another glass substrate and the They were laminated so that they were in contact with the ODF sealant. Then, after irradiation with light of 30,000 J/m ² (365 nm conversion) using a metal halide lamp, the film was heated in an oven at 120° C. for 1 hour. After that, the adhesion of the film was evaluated by measuring the adhesion using a tension/compression tester (manufactured by Imada Seisakusho, model number: SDWS-0201-100SL). The evaluation was “good (○)” when the adhesion was 175 N/cm ² or more, “fair (Δ)” when it was 125 N/cm ² or more and less than 175 N/cm ² , and less than 125 N/cm ² The case where it was was set as "defective (x)". As a result, in this example, the adhesion was 175 N/cm ² , and the adhesion was evaluated as "good (○)".

[Examples 2 to 12 and Comparative Examples 1 to 3]
A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the composition of the liquid crystal aligning agent was changed as shown in Table 4. Further, using the obtained liquid crystal aligning agent, an FFS type liquid crystal display element was produced by the photo-alignment method in the same manner as in Example 1, and the liquid crystal alignment, bright spot suppression, keying durability and adhesion were evaluated. went. Those results are shown in Table 4. In Examples 2, 4, 6, 8 to 10, 12 and Comparative Examples 2 and 3, two types of polymers were used as polymer components, and in Examples 5, 7 and 11, three types of polymers were used as polymer components. It was used. In Table 4, the numerical value in the polymer column represents the blending ratio (parts by mass) of each polymer in solid content with respect to the total amount of 100 parts by mass of the polymer components used in the preparation of the liquid crystal aligning agent.

As shown in Table 4, Examples 1 to 12 using the liquid crystal aligning agent containing the polymer [A] compared to Comparative Examples 1 to 3 using the liquid crystal aligning agent not containing the polymer [A], The liquid crystal orientation, the bright spot suppressing property of the liquid crystal cell, the keying durability and the adhesion of the film were well balanced, and the results were good.

From the above results, it can be seen that the liquid crystal aligning agent containing the polymer [A] can provide a liquid crystal element that is excellent in liquid crystal alignment, keying durability, and adhesion, and in which the occurrence of luminescent spots in the liquid crystal cell is small. It was revealed.

Claims (11)

A step of forming a coating film with a liquid crystal aligning agent containing a polymer [A] having a partial structure (a) represented by the following formula (1);
A step of irradiating the coating film with light to impart liquid crystal alignment ability;
A method for manufacturing a liquid crystal alignment film, comprising:

(In formula (1), A ¹ and A ² are each independently a divalent aromatic ring group, provided that one or both of A ¹ and A ² are —OR ¹ , —NR ² R ³ or It has a structure in which a group represented by —SR ⁴ is bonded to an aromatic ring, R ¹ , R ² and R ⁴ are each independently a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic B ¹ and B ² are each independently a single bond, —O—, —S—, —NR ⁵ —, —CO—, * ¹ —CO—O—, * ¹ —O—CO -, * ¹ -CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ⁶ -, or * ¹ -NR ⁶ -CO-NR ⁷ -, where “* ¹ ” represents A ¹ or represents a bond with A ^2. R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom or a monovalent organic group, X is a divalent hydrocarbon group, and "*" is a bond. represents a hand.) 2. The method for producing a liquid crystal alignment film according to claim 1, wherein the polymer [A] has a structural unit derived from a compound represented by the following formula (2).

(In formula (2), A ¹ , A ² , B ¹ , B ² and X have the same meanings as in formula (1) above.) 2. The method for producing a liquid crystal alignment film according to claim 1, wherein the polymer [A] is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. 4. The method for producing a liquid crystal alignment film according to claim 3, wherein the polymer [A] has a structural unit derived from an aliphatic tetracarboxylic dianhydride. 5. The method for producing a liquid crystal alignment film according to claim 4, wherein the aliphatic tetracarboxylic dianhydride has a partial structure represented by the following formula (4).

(In Formula (4), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each independently a hydrogen atom or a substituent, provided that one of R ¹¹ , R ¹² , R ¹³ and R ¹⁴ The above are substituents."*" represents a bond.) 2. The method for producing a liquid crystal alignment film according to claim 1, further comprising a polymer [B] that does not have the partial structure (a). 7. The method for producing a liquid crystal alignment film according to claim 6, wherein the polymer [B] is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. A photo-alignment agent containing a polymer [A] having a partial structure (a) represented by the following formula (1).

(In formula (1), A ¹ and A ² are each independently a divalent aromatic ring group, provided that one or both of A ¹ and A ² are —OR ¹ , —NR ² R ³ or It has a structure in which a group represented by —SR ⁴ is bonded to an aromatic ring, R ¹ , R ² and R ⁴ are each independently a hydrogen atom or a monovalent organic group, R ³ is a monovalent organic B ¹ and B ² are each independently a single bond, —O—, —S—, —NR ⁵ —, —CO—, * ¹ —CO—O—, * ¹ —O—CO -, * ¹ -CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ⁶ -, or * ¹ -NR ⁶ -CO-NR ⁷ -, where “* ¹ ” represents A ¹ or represents a bond with A ^2. R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom or a monovalent organic group, X is a divalent hydrocarbon group, and "*" is a bond. represents a hand.) A liquid crystal device comprising a liquid crystal alignment film manufactured by the method according to any one of claims 1 to 7. A polymer containing a structural unit derived from a diamine represented by the following formula (3).

(In formula (3), A ³ and A ⁴ are each independently a divalent aromatic ring group, provided that one or both of A ³ and A ⁴ are —OR ^1a or —NR ^2a R ^3a ; The represented group has a structure bonded to an aromatic ring, R ^1a and R ^2a are each independently a monovalent hydrocarbon group, and R ^3a is a hydrogen atom or a monovalent organic group.B ³ and B ⁴ are each independently a single bond, -O-, -S-, -NR ^5a -, -CO-, * ¹ -CO-O-, * ¹ -O-CO-, * ¹ - CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ^6a - or * ¹ -NR ^6a -CO-NR ^7a -, R ^5a is a monovalent organic group, R ^6a and Each R ^7a is independently a hydrogen atom or a monovalent organic group, “* ¹ ” represents a bond with A ³ or A ⁴ , and Y is, when B ³ is —O—, an alkanediyl group having 1 or 2 carbon atoms, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, and when B ³ is * ¹ -O-CO-, an alkanediyl group, a divalent alicyclic hydrocarbon group having an aliphatic hydrocarbon ring with 4 or more carbon atoms, or a divalent aromatic hydrocarbon group, wherein B ³ is other than —O— and * ¹ —O—CO— In some cases, it is a divalent hydrocarbon group.) A diamine represented by the following formula (3).

(In formula (3), A ³ and A ⁴ are each independently a divalent aromatic ring group, provided that one or both of A ³ and A ⁴ are —OR ^1a or —NR ^2a R ^3a ; The represented group has a structure bonded to an aromatic ring, R ^1a and R ^2a are each independently a monovalent hydrocarbon group, and R ^3a is a hydrogen atom or a monovalent organic group.B ³ and B ⁴ are each independently a single bond, -O-, -S-, -NR ^5a -, -CO-, * ¹ -CO-O-, * ¹ -O-CO-, * ¹ - CS-O-, * ¹ -O-CS-, * ¹ -CO-NR ^6a - or * ¹ -NR ^6a -CO-NR ^7a -, R ^5a is a monovalent organic group, R ^6a and Each R ^7a is independently a hydrogen atom or a monovalent organic group, “* ¹ ” represents a bond with A ³ or A ⁴ , and Y is, when B ³ is —O—, an alkanediyl group having 1 or 2 carbon atoms, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, and when B ³ is * ¹ -O-CO-, an alkanediyl group, a divalent alicyclic hydrocarbon group having an aliphatic hydrocarbon ring with 4 or more carbon atoms, or a divalent aromatic hydrocarbon group, wherein B ³ is other than —O— and * ¹ —O—CO— In some cases, it is a divalent hydrocarbon group.)